🚀 go-pugleaf

In article <17898@umd5.umd.edu> matthews@oberon.umd.edu (Mike Matthews) writes:
>In article <1993Jan10.170814.9221@znext.cts.com> zeke@znext.cts.com writes:
>>  so the syntax should be 
>>	'b sd(0,2,0)' to boot off of sd2 partition a.  The NeXT only has one  
>>controller ( unless you have an extra cpu card a la Spherical ) an that one  
>>defaults to 0.  The syntax provided would probably confuse the system, and the
>
>Um, no.  The first number is the SCSI ID, the second is the LUN (which lots
>of people theorize will always be 0 on the NeXTs because they only have one
>SCSI channel; makes sense to me but I can't confirm or deny it personally),
>and the last is the partition number.

Um, close. :-)  The first number is the SCSI controller target number
(usually referred to as the "SCSI ID"), the second is the logical unit
number and the third the partitition number of the disk.

The LUN has nothing to do with the NeXT; it is used when the addressed
SCSI controller on the SCSI bus has more than one unit attached to it.
In days past, when disks didn't have embedded SCSI controllers, you'd
have a seperate SCSI controller on the bus which could have one or
more {ESDI, SMD, ST-506} drives attached to it.  The LUN (Logical Unit
Number) could be used to select amongst the units/disk attached to the
controller.

Louis Mamakos